1. Technical Field
This invention pertains to light fixtures for a plurality of lamps or lamp attachments having two contacts at opposite ends.
2. Background Art
Lamps or lamp attachments which have two contacts at opposite ends, including festune bulbs, tubular lamps, lamp attachments directing current to standard bulbs from opposite ends, and lamp attachments directing light from bulbs in a spotlight or other particular configuration, shall all be referred to herein as "lamps". A number of fixtures are known in the prior art for supplying light by means of a parallel string of lamps. These fixtures are often used to provide either direct or indirect illumination to highlight displays, stair rails and steps, and signs. Lamps supported in a parallel configuration are useful in any linear application that does not require a great deal of scalloping.
Each fixture supporting a parallel string of lamps must accommodate two separated conductive paths, each being connected to the contacts at opposite ends of the bulb, while permitting the bulbs to be lined up so that all of the contacts are in a common axis. To satisfy this requirement, French patent 2451-542 teaches a zig-zag pattern for the conductive paths, running beneath a flat support Alternatively, U.S. Pat. No. 2,298,824 to Darley describes a lamp socket for florescent bulbs, requiring the lamps to be held in an overlapping relationship. Still other designs have utilized side-by-side conductive paths, with complex projecting parts from each conductive path to the opposite contacts on each lamp.
To eliminate the complexity of such flat light fixtures, while providing illumination for a series of parallel lamps, a number of fixtures have been created. For example, U.S. Pat. Nos. 158,221, 4,521,838, and 4,858,088, all to Agabekov, describe light fixtures based on separate conductive paths carried on perpendicular flanges. Similarly, U.S. Pat. No. 4,723,199 to Freed et al. and German Patent No. 87/06326 disclose light fixtures in which separated conductive paths are supported on the back sides of angled flanges. In these angled fixtures, lamps may be held in place by simple brackets, enabling these fixtures to be manufactured more economically and easily than possible with the complicated attachments o wiring required for flat light fixtures known in the prior art.
There are some disadvantages to the angled light fixtures used for supporting a series of lamps. For example, light emitted from a perpendicular fixture necessarily emits direct light to brighten an area of approximately 170 degrees. In contrast, support of a series of lamps on a flat fixture permits light to be emitted over approximately 260 degrees, with only the area directly behind the flat fixture shielded from light. Furthermore, support of a string of lamps by an angled fixture tends to contain heat generated by the lamps, directing unwanted heat to a wall or other support to which the fixture is attached. This contained heat may have detrimental effects, including a reduction in the life of the lamps. Thus, although the light fixtures known in the prior art have particular advantages and purposes, there is a need for a fixture to support a parallel series of lamps, which can be simply constructed, and which will allow light and heat to be disseminated over a larger area than possible with the use of an angled fixture.